The invention relates to a sealing bar for a vacuum drawer for vacuuming food as well as to a vacuum drawer which comprises a vacuum chamber having such a sealing bar.
Vacuuming units comprise a vacuum chamber into which a suitable container, for example in the form of a sealable bag, is placed. An elongate sealing bar extends within the chamber and is installed transversely to the vacuum chamber. The sealing bar is vertically adjustable in the vertical direction. A container filled with food is placed into the vacuum chamber, the latter subsequently being closed in an airtight manner via a cover to generate a chamber vacuum by means of a vacuum pump. Since the sealing bar is first positioned in an open position, the air can also be sucked out of the container. The sealing bar is subsequently vertically adjusted and the bag is clamped between the sealing bar and the counterpart. The required welding energy is supplied to the integrated welding wire or to the welding wire of the sealing bar such that the bag, which frequently contains plastic, is sealed in an airtight manner due to the heat development.
A heat-conductive non-stick coating is typically applied to the upper side of the sealing bar onto which the bag to be welded is placed and said non-stick coating transfers the heat development of the welding wire disposed thereunder to the bag lying directly on the coating. The coating is typically a suitable film which is adhesively bonded to the surface of the single-part sealing bar construction. The constant heat development during the welding process sooner or later produces visual wear phenomena of the non-stick tape, which is characterized by disturbing discoloration. The non-stick function and heat-conductive function of the tape can thereby also be impaired in addition to the visual deficiencies. The non-stick coating should be renewed from time to time for this purpose. An exchange of single films is practically impossible due to the adhesive bond so that the total sealing bar is replaced for reasons of simplicity. The high repair costs caused by the complete replacement are, however, undesirable.